The primary aim of this study is to determine the role of medical care, as well as social and psychological factors in explaining black/white differences in the stage at diagnosis of breast cancer. Black/white differences in stage have been observed in national as well as Connecticut data and contribute to the poorer five-year survival rate among black women. The specific role of medical care factors which influence stage at diagnosis can be appreciated only after thorough exploration of the complex social/psychological factors which either promote or hinder early diagnosis. Previous research suggests that aspects of medical care, like social/psychological factors, may differ for blacks and whites. Specifically, medical care and cancer screening factors are the primary focus of this proposal because of their direct link to stage at diagnosis. Three other categories of factors which may operate indirectly through medical care in affecting stage will also be explored: patient delay in seeking diagnosis once symptoms are detected, knowledge and opinions regarding cancer, and socioeconomic status. This is a retrospective, population-based comparison of black and white breast cancer cases diagnosed in Connecticut between February, 1987 and May, 1989. The study population consists of 148 black women and a 179 white women diagnosed with a first primary breast cancer in 22 Connecticut hospitals. All black breast cancer cases and a random sample of white cases were selected for possible interview. Data were collected by in-person interview and include the following domains of information: 1) general medical care factors; 2) specific factors which describe the steps in the medical care episode which ended with the cancer diagnosis; 3) social-psychological factors; 4) pertinent medical history of cases and reports of cancer in selected blood relatives; 5) health attitudes, beliefs, knowledge, and practices (general and cancer specific); 6) broad sociodemographic and socioeconomic factors. The scope of the data collection instrument will provide a unique opportunity to focus on medical care issues after adjustment for other important contributory factors.